11 Oregon elementary schools banned flavored milk (referred to as chocolate milk in the study) from their cafeterias, in the study from Cornell University Food and Brand Lab.

Total daily milk sales declined by 9.9%, and there was a 29.4% increase in milk waste.

“While removing chocolate milk from school cafeterias may appear to have the immediate benefit of reducing calorie and sugar consumption, there might be unexpected consequences to doing so,” said Andrew Hanks, one of the researchers.

“Our results indicate that when chocolate milk was removed, fewer students took milk, and students wasted more of the white milk they selected.”

The study says eliminating chocolate milk was associated with 6.8% fewer students eating school lunches.

Researchers add students might compensate for a lack of chocolate milk, for example, by eating a dessert.

Children are encouraged to drink milk because it has nutrients essential for bone growth and development. However, chocolate milk can have twice as much sugar as white milk. Some schools have limited or banned it, while others suggest any milk is better than no milk at all.

Eliminating chocolate milk sees an average decrease of 8 grams of sugar and 37 calories in a student’s lunch. However, 1 gram of protein is lost, there is a decrease of five percentage points in the daily recommended intake of calcium, and an additional ½ gram of fat in an average’s student’s lunch, the study suggests.

“Food service managers need to carefully weigh the costs and benefits of eliminating chocolate milk and should consider other solutions, such as making chocolate milk less convenient to select and making white milk appear more convenient, attractive, and normal,” said Hanks.

In the study, chocolate milk was removed in September and October and sales were compared to the same period in the previous year. It found that ‘many students’ were willing to take 1% or skim white milk instead, but fewer units of milk were sold in total.

There are ways milk consumption can be increased without banning other options, the study suggests. Beverage coolers should be stocked with at least some white milk, and preferably a third or more of all milk. White milk could be placed in front of chocolate milk, or included as the ‘default’ drink with meal packages.

“Encouraging students to take white milk can naturally decrease the amount of chocolate milk taken,” said Hanks. “While making white milk relatively more convenient, attractive, and normal to choose (relative to chocolate milk) will lead some children to switch from chocolate to white, it will not influence all children.

“Yet, the remaining question is whether or not drinking chocolate milk is better than drinking an alternative caloric drink, such as a sports drink, or even not eating a school lunch at all.”